Cesium carbonate → Methyl 2-methyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1h-pyrazol-1-yl)propanoate
Reaction equation
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[N:11][NH:12][CH:13]=2)[O:3]1.[CH3:15][O:16][C:17](=[O:22])[C:18](Br)([CH3:20])[CH3:19].C([O-])([O-])=O.[Cs+].[Cs+]>CN(C=O)C>[CH3:15][O:16][C:17](=[O:22])[C:18]([CH3:20])([N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1)[CH3:19]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 90 °C
Procedure
To a solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (5 g, 25.77 mmol) and 2-bromo-2-methyl-propionic acid methyl ester (12.6 g, 27.06 mmol) in DMF (85 mL), was added Cs2CO3 (12.6 g, 38.65 mmol). The reaction mixture was heated to 90° C. in an oil bath overnight. The reaction solution was cooled to room temperature, and partitioned between water and ethyl acetate. The combined ethyl acetate solution was washed with water five times, dried over Na2SO4, and concentrated to give the product 2-methyl-2-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-pyrazol-1-yl]propionic acid methyl ester (4.776 g, 63% yield).
Workup
- temperatureThe reaction solution was cooled to room temperature
- custompartitioned between water and ethyl acetate
- washThe combined ethyl acetate solution was washed with water five times
- dry with materialdried over Na2SO4
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-ccc6369f61724fe783524ef71e9679e5
- Source dataset
- uspto-grants-2010_12
- Patent number
- US07858643B2
Reaction notes
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